Add a [rtc_]build_with_neon variable to unify conditions.

webrtc/modules/audio_processing/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("//build/config/arm.gni")
 import("//third_party/protobuf/proto_library.gni")
@@ skipping 158 matching lines @@
       "ns/ns_core.c",
       "ns/ns_core.h",
       "ns/windows_private.h",
     ]
   }
 
   if (current_cpu == "x86" || current_cpu == "x64") {
     deps += [ ":audio_processing_sse2" ]
   }
 
-  if (rtc_build_armv7_neon || current_cpu == "arm64") {
+  if (rtc_build_with_neon) {
     deps += [ ":audio_processing_neon" ]
   }
 
   if (current_cpu == "mipsel") {
     sources += [ "aecm/aecm_core_mips.c" ]
     if (mips_float_abi == "hard") {
       sources += [
         "aec/aec_core_mips.c",
         "aec/aec_rdft_mips.c",
       ]
@@ skipping 41 matching lines @@
 
     if (is_posix) {
       cflags = [ "-msse2" ]
     }
 
     configs += [ "../..:common_config" ]
     public_configs = [ "../..:common_inherited_config" ]
   }
 }
 
-if (rtc_build_armv7_neon || current_cpu == "arm64") {
+if (rtc_build_with_neon) {
   source_set("audio_processing_neon") {
     sources = [
       "aec/aec_core_neon.c",
       "aec/aec_rdft_neon.c",
       "aecm/aecm_core_neon.c",
       "ns/nsx_core_neon.c",
     ]
 
+    if (current_cpu != "arm64") {
+      # Enable compilation for the NEON instruction set. This is needed
+      # since //build/config/arm.gni only enables NEON for iOS, not Android.
+      # This provides the same functionality as webrtc/build/arm_neon.gypi.
+      configs -= [ "//build/config/compiler:compiler_arm_fpu" ]
+      cflags = [ "-mfpu=neon" ]
+    }
+
+    # Disable LTO due to compiler bug.

[kjellander_webrtc, 2015/06/18 09:06:23]

Add link to the bug as previous comment.

[Andrew MacDonald, 2015/06/25 01:09:09]

Done.

+    if (rtc_use_lto) {
+      cflags -= [
+        "-flto",
+        "-ffat-lto-objects",
+      ]
+    }
+
     configs += [ "../..:common_config" ]
     public_configs = [ "../..:common_inherited_config" ]
 
     deps = [
       "../../common_audio",
     ]
-
-    # Enable compilation for the ARM v7 Neon instruction set. This is needed
-    # since //build/config/arm.gni only enables Neon for iOS, not Android.
-    # This provides the same functionality as webrtc/build/arm_neon.gypi.
-    # TODO(kjellander): Investigate if this can be moved into webrtc.gni or
-    # //build/config/arm.gni instead, to reduce code duplication.
-    # Remove the -mfpu=vfpv3-d16 cflag.
-    configs -= [ "//build/config/compiler:compiler_arm_fpu" ]
-
-    # "-mfpu=neon" is not requried for arm64 in GCC.
-    if (current_cpu != "arm64") {
-      cflags = [ "-mfpu=neon" ]
-    }
-
-    # Disable LTO in audio_processing_neon target due to compiler bug.
-    if (rtc_use_lto) {
-      cflags -= [
-        "-flto",
-        "-ffat-lto-objects",
-      ]
-    }
   }
 }